Benchmark: deleting multiple values from array

Script Preparation code:

var len = 100000;
var arr = Array(len).fill(42);
var deleteIndexes = Array.from(Array(1000), () => (Math.random() * len)|0);
console.log("deleteIndexes", deleteIndexes);

Tests:

splice
for (const i of deleteIndexes) { arr.splice(i, 1); }
delete + Object.values
for (const i of deleteIndexes) { delete arr[i]; } let res = Object.values(arr);
filter
arr.filter((val, idx) => deleteIndexes.includes(idx))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
splice
delete + Object.values
filter

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared options, pros and cons of each approach, library usage, special JS features or syntax, and alternative approaches.

**Benchmark Overview**

The benchmark tests three different approaches to deleting multiple values from an array in JavaScript:

1. Using `splice()`
2. Using `delete` operator followed by `Object.values()` to create a new array
3. Using `Array.prototype.filter()` with the `includes()` method

Each test case has a unique name, and their respective benchmark definition scripts are provided.

**Options Compared**

The three options being compared are:

1. **splice()**: A built-in JavaScript method that modifies the original array by removing elements at specified indices.
2. **delete + Object.values()**: Using the `delete` operator to remove individual elements from the array, and then using `Object.values()` to create a new array with the remaining elements.
3. **filter() with includes()**: Using the `includes()` method to check if an index exists in the `deleteIndexes` array before including it in the filtered array.

**Pros and Cons of Each Approach**

1. **splice()**:
	* Pros: Efficient, fast, and straightforward.
	* Cons: Modifies the original array, which may be undesirable depending on the use case.
2. **delete + Object.values()**:
	* Pros: Creates a new array with remaining elements, preserving the original array's integrity.
	* Cons: May be slower due to the overhead of creating a new array using `Object.values()` and potentially slower delete operations.
3. **filter() with includes()**:
	* Pros: Preserves the original array's integrity like `delete + Object.values()`, but with a simpler syntax.
	* Cons: May be slower than `splice()` due to the overhead of calling `includes()` for each index.

**Library Usage**

None of the benchmarked scripts use any external libraries.

**Special JS Features or Syntax**

The benchmark uses two special features:

1. **Template literals**: Used in the `Script Preparation Code` and `Individual test cases` sections.
2. **Array.from()**: Used to create an array from an iterable (in this case, another array).

Note that these are not critical features, as they are part of the JavaScript language.

**Alternative Approaches**

Some alternative approaches to deleting multiple values from an array include:

1. Using `map()` and slicing: Create a new array with only the desired elements using `map()`, and then slice it to remove unnecessary elements.
2. Using `reduce()` and filtering: Use `reduce()` to iterate over the original array, applying a filter function to each element.
3. Using `forEach()` and splicing: Use `forEach()` to iterate over the original array, modifying it in place using `splice()`.
4. Using `set`: If you're using modern JavaScript (ES6+), you can use `Set` data structure to remove duplicates from an array.

Each of these approaches has its own trade-offs and may be more or less suitable depending on your specific use case.

Related benchmarks:

deleting multiple values from array (version: 4)

Comparing performance of: splice vs delete + Object.values vs filter

Created: 3 years ago by: Registered User

Jump to the latest result

splice

delete + Object.values

filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):